This invention relates to an aseptic packaging system, more specifically to a method of aseptically filling a container and to a container for use in that method.
Where it is desired to fill a sterilised container with flowable materials such as foodstuffs or the like it is important that bacteria and other micro organisms are not introduced into the container during the filling process. Also, once filling has been completed, it is important that the container is sealed in such a manner that contaminants are not able to enter the container during transportation or storage through the sealed filling inlet.
Various prior art patents have addressed the aforementioned problems and reference may be made to U.S. Pat. No. 4,805,378 (Anderson), U.S. Pat. No. 2,930,170 (Holdsman et al), U.S. Pat. No. 4,542,530 (Thomas et al) and U.S. Pat. No. 4,672,688 (Kalipsarkis). These prior art patents describe systems, which are successful to a greater or lesser extent. However, the prior art systems do suffer from deficiencies, at least under some filling circumstances.
For example, U.S. Pat. No. 4,805,378 discloses an arrangement in which a membrane is positioned across the mouth of the filling inlet, which is pierced during the filling process. Generally this piercing is achieved by a cutting head which makes a pair of straight incisions, crossed at right angles, passing through the centre of the membrane and extending radially outwards to a point just inside the outer flange of the upstanding gland or collar. Accordingly, as the liquid or liquid like product flows into the bag container to fill it, the four cut tips or xe2x80x9cpetalsxe2x80x9d of the membrane turn inwardly with the flow and extend towards the inner end of the collar where it is connected to the container in the region that it subsequently sealed as described in the patent specification. This arrangement is sometimes unreliable in that the four petals are difficult to clean underneath to remove remnants of the packaged product inside the collar during the flushing cycle. Also, the petals tend to reduce the flow rate of product into the container during the filling, which can be disadvantageous from a production point of view with viscous or particulate containing products.
There is furthermore a risk that the tips of the petals might wrap underneath the inside corner of the collar and be caught up in the subsequent final heat sealing operation. If this were to happen there would be potential for a leakage path to bypass the seal or, at least, a potential source of failure of the seal.
There is a further requirement of the industry to have an appropriate arrangement for connecting decanting equipment to the filling gland or collar. The aforementioned petals often serve as an impediment to subsequent use of the fitment for attachment of recloseable closures and other devices for dispensing the product by the end user, and also prevent close inspection of the inner sealed membrane for cleanliness and sealing performance. Many commercial tap and dispensing systems incorporate a standard female thread form in their attachment means and many have been derived from systems used on commercial rigid containers such as plastic bottles. It is desirable to be able to fit these standard commercially available dispensing systems to an aseptic outlet port without modification of the connection arrangement.
The invention provides an aseptic container for use in an aseptic packaging system, said container comprising a wall which encloses a volume in which the material to be packaged will be received, a generally cylindrical gland fitted to said wall, said gland having an inner sealing surface which is in communication with said volume, and an outer sealing surface, and a passage through the gland, the inner and outer sealing surfaces extending around said passage, an inner sealing membrane adapted to seal with said inner sealing face of the gland, an outer sealing membrane adapted to seal said outer sealing face of the gland, and connection formations formed on the gland for securing a filling or dispensing head or nozzle to the gland in use.
The invention also provides an aseptic container for use in an aseptic packaging system, said container having a wall which encloses a volume in which the material to be packaged will be received, a generally cylindrical gland fitted to said wall, said gland having an inner sealing surface which is in communication with said volume, and an outer sealing surface, and a passage through the gland, the inner and outer sealing surfaces extending around said passage, an inner sealing membrane adapted to seal with said inner sealing face of the gland, an outer sealing membrane adapted to seal said outer sealing face of the gland, and connection formations formed on the gland for securing a filling or dispensing head or nozzle to the gland in use, wherein said outer sealing membrane being secured to a collar that is adapted to be secured to said gland via said connection formations.
The connection formations are preferably screw threads, preferably on the outer surface of the gland.
Preferably the first sealing membrane is the form of a flap which is partially secured to the inside face of the gland and which is adapted to be welded or otherwise secured to the inside face after the container has been filled with a selected filling material.
The outer sealing membrane can either be secured to the outside face of the gland or may be secured to a collar which is adapted to be screwed onto said threads. Optionally said collar may be sealed to said gland by a bevelled engaging sealing surface, an elastomeric gasket, a sealing compound, heat sealing, or some other sealing arrangement for ensuring a contamination free seal.
Screw threads are preferably formed on the outer face of the gland, which have a pitch and configuration suitable for receiving a conventional tap or other dispensing system.
According to the second aspect of the invention there is provided a method of a subject filling a container which comprises the steps of:
providing a container with a filling gland having an inner sealing surface to which a inner sealing membrane is partially secured, and an outer sealing surface to which a outer sealing membrane is sealed, a passage passing through said gland, and either external or internal screw threads formed on said gland;
bringing a filling head into engagement with the gland and sterilising the outer surface of the outer membrane;
piercing the outer membrane and filling the container with a selected material; and
sealing the inner membrane by welding the inner membrane to the inner sealing surface.
Optionally the filling process may be completed by removing said filling head and screwing a cap or other closure onto said screw threads.
These and further features of the invention are made apparent from the description of two embodiments set out below by way of example. In the description references made to the accompanying drawings but the specific features shown in the drawings should not be construed as limiting on the invention.